A. Carvalho

SPICY 30021: an embedded bona fide FUor with a mid-infrared precursor

Zhen Guo, Calum Morris, Vitor Fermiano +37

Unstable mass accretion in young stellar objects (YSOs) often leads to observable outbursts, which play a key role in stellar mass assembly during pre-main-sequence evolution. The…

Conspicuous Gas, Cryptic Dust: Spectroscopy and Chromaticity of Complex Periodic Variables

Luke G. Bouma, Facundo Perez Paolino, Lynne A. Hillenbrand +17

Complex periodic variables (CPVs) are young low-mass stars whose light curves show periodic dips indicative of transiting corotating material. The origin and composition of this ma…

Hot water emission during an outburst in a classical T Tauri star

Zhen Guo, Javier Osses, Vitor Fermiano +34

In this paper, we present observations of an eruptive young star in the Rosette Nebula, identified by the Gaia Science Alerts system using Gaia time series data. We aim to investig…

A Parameterized YSO Accretion Disk Model with Increasing Accretion Rate: Predicted Outburst Lightcurves

Gautam Das, Lynne A. Hillenbrand, Adolfo S. Carvalho

A sub-class among Young Stellar Objects (YSOs), known as FU Ori type stars, undergo sudden rises in luminosity by several orders of magnitude on timescales of a few months to a few…

Quantitative Spectroscopic Diagnostics for FU Orionis-Type Young Stellar Objects

Evan R. Portnoi, Lynne A. Hillenbrand, Adolfo S. Carvalho

We present near-infrared spectroscopic diagnostics that can be used to identify FU Orionis stars (FUOrs). FUOrs are young stellar objects (YSOs) that are currently in a state of ex…

The FUor Mass Distribution Matches the Solar Neighborhood IMF: Evidence for a Universal Eruptive Phase

Adolfo S. Carvalho, Lynne A. Hillenbrand

Eruptive accretion events are expected to play an important role in the mass buildup stage of individual star formation. FU Ori objects (FUors) experience the most extreme eruptive…

A New FU Orionis Accretion Outburst in the W5 HII Region

Lynne A. Hillenbrand, Matthew J. Graham, Mansi M. Kasliwal +9

We announce a recently detected outburst that is currently only a few months old, and probably of FU Orionis type. The progenitor to the outburst was an emission-line, flat-spectru…

The Near-Ultraviolet Spectra of FU Orionis Accretion Disks

Adolfo S. Carvalho, Lynne A. Hillenbrand, Gregory J. Herczeg +1

We present the results of the first high-sensitivity NUV (1800 to 3200 Å) survey of FU Ori objects, using the \textit{Hubble Space Telescope} (HST) STIS spectrograph. We compare ne…

astro-ph.SR2025★ 8 cited

The Outbursting YSOs Catalogue (OYCAT)

C. Contreras Peña, J. -E. Lee, G. Herczeg +39

YSOs can display unpredictable and high-amplitude rises in brightness that can last from a few months to possibly over 100 years. These types of outbursts are explained by large ch…

The Hot Inner AU of V883 Ori

Adolfo S. Carvalho, Lynne A. Hillenbrand, Ágnes Kóspál

The V883 Ori system is a rapidly accreting young stellar object that has been used as a laboratory for studying the molecular inventory of young circumstellar disks with high lumin…

FUOr-Aur 0544+3330: A New YSO Outburst in the Outskirts of Auriga OB1, Viewed Face-On

Lynne A. Hillenbrand, Adolfo S. Carvalho, Dan Stern +5

We present a newly appreciated FU Ori outburst event that began in 2019 and reached a peak in early 2021. Suspected young stellar object WISE J054452.25+333009.6 experienced substa…

Spectral Biases, Starspot Morphology, and Dynamo Transitions on the Pre-Main Sequence: Insights from the X-Shooter WTTS Library

Facundo Pérez Paolino, Jeff Bary, Benjamin Horner +2

Starspots are ubiquitous in young, low-mass stars, yet their impact on the spectral classification and fundamental parameter inference of pre-main sequence stars (PMS) has been lar…

Rosette Nebula Outburst Gaia 24djk from the Young Stellar Object V557 Mon

Adolfo S. Carvalho, Lynne A. Hillenbrand

A previously faint young stellar object (YSO), V557 Mon, rapidly brightened in late 2024 and is currently at least $Δ G = 3.3$ magnitudes brighter than its typical pre-outburst bright…

Bolometric Corrections for FU Ori Object Accretion Disk Luminosities

Adolfo S. Carvalho, Lynne A. Hillenbrand

The accretion luminosity of an FU Ori disk is a fundamental system parameter, but a challenging one to estimate for all but the most well-studied systems. FU Ori objects are dynami…

The FUV Spectrum of FU Ori South

Adolfo S. Carvalho, Gregory J. Herczeg, Kevin France +1

The eruptive YSO FU Ori is the eponym of its variable class. FU Ori stars are known to undergo outbursts with amplitudes of $> 4$ magnitudes in the $V$ band and durations of several…

An FUV-detected Accretion Shock at the Star-Disk Boundary of FU Ori

Adolfo S. Carvalho, Lynne A. Hillenbrand, Kevin France +1

FU Ori objects are the most extreme eruptive young stars known. Their 4 to 5 magnitude photometric outbursts last for decades and are attributed to a factor of up to 10,000 increas…

An Expanding Accretion Disk and a Warm Disk Wind As Seen In the Spectral Evolution of HBC 722

Adolfo S. Carvalho, Lynne A. Hillenbrand, Jerome Seebeck +1

We present a comprehensive analysis of the post-outburst evolution of the FU Ori object HBC 722 in optical/near-infrared (NIR) photometry and spectroscopy. Using a modified viscous…